1. Field of the Invention
Field is that of electronics and computers. Microprocessors, radio signals, and CRT displays are involved.
2. Description of the Prior Art
Poignet et al, U.S. Pat. No. 4,361,848 discusses a teletext system in which the news is formed into pages and transmitted on the vertical retrace of a TV signal. The entire text of the news is transmitted repetitively. The user pulls selected pages for viewing as they fly by. A first objection to the system is that there is a delay between the time the user specifies which page he desires to read and the time the specified page is delivered to his display. A mean time of 15 seconds is indicated. For the Quinews the desired page appears instantly. A second objection is that the piece of information is transmitted a thousand times (approximately), which means that another system (such as the Quinews) which transmits the text only once, can transmit a thousand times as much code. Expressed another way, a system such as the Quinews requires only one thousandth the bandwidth as does a Poignet system. These advantages of the Quinews over the Poignet system result from the fact that the Quinews provides mass storage at the user site while Poignet does not.
Cox U.S. Pat. No. 4,388,645 discusses a teletext system in which satelite transmission of coded pages to a cable head-end station is provided. The station stores the coded pages and then converts and retransmits the news content thereof as ordinary TV pictures. Retransmission is to end users of the news. No code is transmitted to the user site. Operationally the system is identical to the TV newscast. The only difference is that pages of print are transmitted instead of pictures. The user must watch whatever is transmitted from the head-end station. He may not select those stories in which he is interested and pass the others by. He may not read any story in depth. Whereas, with the Quinews he reads only those articles in which he is interested--and he can read them in much greater depth. Mass storage for the Cox system is at the head-end station. No storage whatsoever is at the user site. The bandwidth required for the transmission is 4.5 MHz, about 4,000 times that required by the Quinews.
Marti U.S. Pat. No. 4,303,941 describes a system similar to that of Poignet. Only a single page of display storage is at the receiver--no mass storage. Mass storage is at the transmitter. Consequently the Marti system suffers the same shortcomings as does the system of Poignet.
The following U.S. patents are cited as being of interest.
Ciciera, U.S. Pat. No. 4,233,628
Guillou U.S. Pat. Nos. 4,323,921 and 4,337,483
Hernandez et al U.S. Pat. No. 4,308,558
Marti et al U.S. Pat. No. 4,290,062
Parsons U.S. Pat. No. 4,099,258
Sechet et al U.S. Pat. No. 4,354,201